Trainers need to collect a certain number of Gym Badges in order to qualify for a region's Pokémon League. Young Trainers usually begin their initial Pokémon journey by traveling from city to city in order to collect them. Badges are small enough to fit easily between one's thumb and index finger and can be pinned to a shirt or kept in a Badge case.

Effects

Stat boost

In Generations I-III, some Badges boost a certain stat or stats of the player's Pokémon. This boost is applied only in internal battles, not link battles. In Generations I and II, the stat or stats are increased by 12.5%; in Generation III, the stat or stats are increased by 10%. This boost does not exist from Generation IV onward.

In Generation I, this boost is reapplied whenever the player's Pokémon's stats are raised or lowered, allowing boosts to be stacked (this stacking effect is lost if the Pokémon levels up). In Generation II, if the attack is a critical hit and the attacker's used offensive stat stage is less than or equal to the opponent's defensive stat stage, all Badge boosts are ignored.

Note that in Generation I the game states that the Thunder Badge raises Speed and the Soul Badge raises Defense, but these are not the actual effects caused.

Type boost

In Generation II, every Badge boosts the power of the moves of a certain type by 12.5% (1/8), despite never being referenced in the games. The type strengthened matches the type theme of the Gym (for example, Zephyr Badge boosts the Flying-type). These boosts work similarly to the way same-type attack bonus (STAB) boosts work, and are, in fact, calculated in-between weather modifiers and STAB.

HM moves

While Trainers can teach their Pokémon HM moves and use them in battle, Trainers require the appropriate Badge to use them in the overworld in GenerationsI through IV as well as Generation VI. In Generation V only, Badges are not needed to use HM moves in the overworld.

Poké Mart stock

From Generation IV onwards, the number of Badges a Trainer possesses affects which items Poké Marts sell. The more Badges, the more items that become available for purchase, with more expensive items generally appearing after more Badges are obtained.

Pokémon League

In the games, in order to enter the Pokémon League and challenge the Elite Four and Champion, the player must have all eight Badges from that region (or in the case of the Indigo Plateau, either Kanto or Johto). In Unova, Kalos, and Generation I/III Kanto, Badges are checked individually through a series of Badge Check Gates; in Hoenn, Sinnoh, and Generation II/IV Kanto, Badges are checked all at once.

Sinnoh League

When Badges are touched in the games, they play a single note, and will make a musical C major scale when all eight Badges are collected. When a player rubs the stylus across them numerous times to polish them (as they gradually tarnish), they will begin to shine. This process can be continued until four sparkles are visible. The musical notes are also the most clearly defined and accurately tuned when there are four sparkles.

Unlike other generations, it is the number of Badges that determines which outsider Pokémonobey the Trainer, rather than the Badges themselves (this distinction is important owing to the fact that the order of obtaining the Cobble, Fen, and Relic Badges can differ). For every second Badge the maximum level of obeying Pokémon increases (0 Badges—level 10; 2 Badges—level 30; 4 Badges—level 50; 6 Badges—level 70; 8 Badges—level 100). The number of Badges collected also affects the items that the player can purchase in Poké Marts.

Unova League

Unlike previous Badges, the level at which traded Pokémon will obey the player goes up by ten per Badge, rather than the previous system of rising twenty levels after every even-numbered Badge. They can be polished like Sinnoh's Badges, although they do not make different notes when polished at the same level. Instead, the picture of the Gym Leader from whom the Badge was earned gets grayer.

In Black 2 and White 2 the Badges no longer dull over a period of time, and Sinnoh's notes were reintegrated into the Badge screen.

Although Badges are not required to use any of the HMs outside of battle, some HMs cannot be obtained until after obtaining certain Badges. However, they are not required, as traded Pokémon that have learned an HM move in another game can still use the HM move before acquiring any Badges.

It is shaped like a bow tie, similar to those worn by the Striaton Gym Leaders. It may also bear a resemblance to an opened pea pod, which contains two large peas; one green and one blue, with a smaller red pea at the center.

Trainers do not necessarily have to win a battle with the Gym Leader in order to earn a Badge, and Gym Leaders can be quite lenient about giving out Badges. For example, Ash was awarded several Badges during the original series because of his kind heart and determination; Misty has berated Ash on several occasions because he did not properly earn all of his Kanto Badges, arguing that he really only earned three Badges (the Thunder, Soul, and Volcano Badges) and the other five Badges were given to him on technicalities. In Flint Sparks the Fire!, the Sunyshore Gym was shown to be handing out free Beacon Badges. The Orange Crew all have entire Gym matches devoted to unconventional battling styles.

In Kalos, due to Clemont's perception of an ideal challenger of the Lumiose Gym, he programmed the Clembot—the substitute Gym Leader—to throw out challengers who did not have four Kalos League Badges. As a result, when Ash attempted to challenge the Gym shortly after arriving in the Kalos region, Clembot acted according to its programming and threw him out. After Clemont reprogrammed the Clembot, he removed the Badge restriction, but Ash indicated he would still collect four Badges before challenging Clemont himself at the Gym.

Many fellow Trainers that Ash has encountered have been shown to have Badges that do not exist in the games, such as Gary earning ten Badges in Kanto, indicating that there are more than eight Gyms in each region. Other Badges observed in the anime which do not correspond to known Badges suggest that there are at least nine Gyms in Hoenn, 11 in Sinnoh, 14 in Unova, and 11 in Kalos. Despite this, Ash's Badge case has frequently had indents specifically shaped for the Badges that appear in the games. However, Trainers only need eight to qualify

It is also implied in the anime that a Gym Badge serves as a primary ID for a Gym Leader (and probably a secondary ID for a Trainer). Brock has used his Boulder Badge to identify himself in order to clear his name from any accusations of stealing parts from a machine shop in Cerulean City.

Additionally, Badges are not the only way to enter the Indigo Plateau Conference. Pokémon Tech, a boarding school for Pokémon Trainers, is an expensive school for children, where moving up a grade is the equivalent of winning two Gym Badges. Upon graduation, students may immediately apply for entry in Kanto's League Conference. Alternatively, Trainers can take the Pokémon League Admissions Exam, which awards a single Badge that grants entry to the Indigo Plateau Conference on its own; it is convenient for people whose age, health, or work keeps them from traveling around to collect Badges.

Alternative Badges in the anime

So far, Ash has only obtained Badges that are obtainable in the games, with the notable exception of those he obtained in the Orange Archipelago. Several unknown Badges can be seen at the beginning of Mystery at the Lighthouse, while many Trainers Ash has met have had Badges that differ from those that are obtainable in the games. This suggests that there are Gyms in locations which do not appear in the games and therefore more than eight Gyms in each region. Trainers with Badges not seen in the games include:

Gary

Gary acquired more than the standard eight Kanto League Badges, thus leading to confusion as to whether or not there is a fixed number of Badges that can be given out in a particular region. By The Battle of the Badge, he is shown to have at least ten Badges, only three of which correspond to known Kanto Badges, suggesting there are at least fifteen Gyms in Kanto. Incidentally, this would provide one Gym for each of the (at the time) 15 types.

Otoshi

In addition, before Ash competes in the Indigo League, a Trainer named Otoshi is shown in the episode Bad to the Bone; he owns eight Badges, but only shares four in common with Ash; later in the episode another Trainer is seen with eight other completely different Badges altogether. In total, Ash, Gary, Otoshi, and the other Trainer display 27 different types of Badges, so there must be at least this number of Gyms in Kanto at the time, assuming they are all from the same region. However, Sakura, a Trainer on her journey, was shown to be collecting Badges from both Kanto and Johto, so it is unclear what the specific rules are for competing in championship tournaments.

On closer inspection, Otoshi's Badges each look somewhat similar to Ash's Badges and only differ in size and shape. Similarly, what can be identified as a Soul Badge, Thunder Badge, Marsh Badge, and Volcano Badge slide across the screen every time his Marowak knocks out a Pokémon in his flashback. His Badges are in this order from upper-left to bottom-right: Thunder, ? (Rainbow), Cascade, Volcano, Marsh, Soul, Boulder, and Earth. This hints that there may be different varieties of the same Badge.

Morrison

At the Hoenn Pokémon League Championship in Saved by the Beldum!, Morrison is shown to have an eighth Badge different from Ash's, suggesting that there are at least nine Gyms in Hoenn.

Mismagius

In Ash's dream in Malice in Wonderland, Ash has many Badges that haven't been on-screen before, as well as some older Badges. Considering it was only a dream, it is possible that some of the Badges seen don't exist at all.

Barry

In Barry's Busting Out All Over!, it shows that Barry has three Badges. While the Forest Badge and the Mine Badge are no different, Barry has a third Badge that is different from the eight Sinnoh Badges. In Fighting Ire with Fire!, Barry was revealed to have obtained eight Badges already, two more of which are different. This means that there are at least 11 Gyms in Sinnoh. The same unknown red Badge that Barry owns is shown at the end of An Old Family Blend!.

Nando

In Last Call, First Round! it is revealed that Nando has acquired seven Badges, two of which are unknown. These two Badges are the same as two of Barry's unknown Badges.

Trip

Cameron

In Goodbye, Junior Cup - Hello Adventure!, Cameron revealed all seven of the Badges he collected, four of which are known and three of which are unknown. Two of those unknown Badges are the same as Trip's. Since there are 10 Badges in Unova in the games (due to two of them being replaced in Black 2 and White 2), this means that there are at least 14 Gyms in Unova.

Sawyer

In A Fashionable Battle!, Sawyer stated that he had earned one Badge. Later, in From A to Z!, he was revealed to have earned four more Badges, including three unknown ones. This means there are at least 11 Gyms in Kalos.

Non-Gym Badges

Several Badges have appeared in the anime that are not official Gym Badges.

In the Indigo League, Trainers can take the Pokémon League Admissions Exam, which awards a single Badge that grants entry to Indigo Plateau Conference on its own, replacing the requirement to collect Gym Badges. It is convenient for people whose age, health, or work keeps them from traveling around to collect Badges.

In the manga

In the Pokémon Adventures manga

Platinum's Sinnoh Gym Badges

In Pokémon Adventures, Badges have mystical and mysterious qualities that can somehow increase the power of the Pokémon owned by the Trainer who wields the Badges, just as the Boulder Badge increases the Pokémon's Attack stat in the games. In addition, Badges that don't allow higher leveled Pokémon to obey, such as the Soul Badge, do indeed allow the wearer to control even Legendary Pokémon such as Articuno.

It is not known what sort of material Badges are made of, but it has been confirmed that the Gym Leaders each own a Badge made of different material than the kind given out to normal Trainers, as that is how the Masked Man's identity was narrowed down to among the 16 known Gym Leaders when Aibo scraped off a part of his hidden Badge with his Scratch attack.

Badges are not required to enter the Pokémon League tournament; however, without eight Badges corresponding to their home region, a Trainer must battle their way in to qualify for the finals. This ruling was introduced during a Pokémon Association meeting in the Gold, Silver & Crystal chapter, to give Trainers incentive to challenge Gym Leaders, and remove the perception of Badges being seen as tools for evil. In the Black & White chapter, a last-minute advancement of the date of the Unova League tournament also restricted the eligible challengers to those with all eight of the region's Badges.

Four main characters have actively been collecting Gym Badges: Red, who managed to collect seven Kanto Badges (missing the Earth Badge); and Sapphire, Platinum and Black, all of whom managed to collect all of the Badges in their respective regions. Other characters have also gathered Badges, such as Cheren and Silver.

In The Electric Tale of Pikachu manga

Ash's Kanto Badges

Ash's Orange League Badges

In The Electric Tale of Pikachu, Badges work in a way similar to the anime, however, there are some minor differences. All Badges have the Pokémon League logo printed on them.

In addition, Pokémon Trainers are organized by class, much like Pokémon Tech "Class D", "Class C" and so forth. Badges increase the rank of the Trainer who owns them. Ash once believed that he could increase his rank by capturing rare wild Pokémon, however this was not the case.

Ash has obtained eight Badges from Kanto, but only three (Boulder, Cascade, Earth) actually matching known Badges, and another three lookalike Badges (resembling the Soul, Marsh, and Volcano). Ash also obtained four Badges from the Orange Islands, but none of them match any known Badges.

In Pokémon Live!

In Pokémon Live!, Giovanni offers the Diamond Badge to Trainers who defeat his MechaMew2. He gives Ash the Diamond Badge prior to the battle, believing that Ash will never win. However, Ash defeats Giovanni with Mewtwo's assistance, proceeding to give the Diamond Badge to Misty as a belated birthday gift. Pokémon Live! is not in continuity with the anime, and the Diamond Badge is not mentioned elsewhere in the series; however, it is the inspiration for DiamondShipping's name.

Trivia

The Earth Badge's design in the anime

Official artwork of the Earth Badge

In the Pokémon Project Studio Red and Blue computer programs, the Soul and Marsh Badges' names are reversed, with the pink heart-shaped Badge being the Marsh Badge and the yellow circular Badge being the Soul Badge. Several anime and game handbooks also make this same switch. This appears to be because of an initial error in naming the Badges in Red and Blue. A soul would be more attuned to psychic abilities and one finds poisonous gases in a marsh.

Official artwork of the Earth Badge (featured in media such as Pokémon Project Studio Red and Blue and Extreme Pokémon: The Guide for the Ultimate Fan) differs significantly from its appearance in the games, anime, manga, and TCG. The design in its official artwork resembles a plant, whereas its other design resembles a feather.

The Orange League is the only known Pokémon League with fewer than eight Badges.

It is possible to obtain certain Badges in a non-linear order. The most notable example of this are the Kanto Badges in GenerationsII and IV, which can be obtained in virtually any order, although the Earth Badge must be obtained last in Generation IV.

In Generation III, the only Gym that can be skipped entirely is the Fortree Gym. The player can get to the point in the game where the guards at the Pokémon League check to see if the player has received all eight Badges. This is not the case with the Dewford Gym as it must be defeated in order for the player to fight Norman, though it can be put off until after Flannery has been defeated.